I used the Raid, but as far as the roaches were concerned I may as well have been spraying them with fruit juice. I finally found a place that sold Bengal. It took a couple of applications, but it has been almost four months since I saw a roach in my kitchen. Besides spraying cracks and crevices, I poked little pin holes in the wall and inserted the straw. The first application was the most satisfying because they actually started coming out in droves and dying on the floor. You have to be patient, because after I sprayed, I would see one once in a while until I followed up with another application and they all disappeared.